14
ACB Interface — The  ACB  interface  is  a  dry  contact
board that  can  output  up  to  four  signals  controlling  devices.
Refer to Fig. 23 for connecting devices to ACB interface board.
Fig. 23 —ACB Interface
START-UP
Pre-Start Check — 
Once installation is complete, make
the following pre-start checks:
1. All indoor and outdoor units are properly installed.
2. All piping and insulation is complete.
3. All electrical  connections  (both  power  and  control)  are
properly terminated.
4. All condensate drains are installed correctly.
5. The power supply is of the right voltage and frequency. 
6. The  units  are  properly  grounded  in  accordance  with
current electrical codes. 
7. Suction  and  liquid  line  isolation  valves  are  in  open
position.
System Operation Check — Once  the  installation
and pre-start checks are completed, follow these steps:
1. Using  the  remote  controller,  select  cooling  or  heating
mode to check the operation of the system.
2. While the system is in operation, check the following on
indoor unit:
a. Switches  or  buttons  on  the  remote  controller  are
easy to push.
b. Indicator light is showing normal operation and no
error is indicated.
c. Swing  mode  of  air  louvers  is  working  (if
applicable to unit). 
NOTE: When attaching a supply duct to the side of the cas-
sette to feed a small adjacent space, the corresponding louver
must be closed to deliver airflow to the supply duct.
d. Drain pump operation is normal (if applicable).
e. No abnormal vibration or noise is noticed.
3. While the system is in operation, check the following on
the outdoor unit:
a. No abnormal vibration or noise is noticed.
b. Condenser fan is in operation.
c. Indicator light is showing normal operation and no
error is indicated.
NOTE:  If  the  unit  is  turned  off  or  restarted,  there  is  a  time
delay of 3 minutes for compressor to start from time power is
restored.
MAINTENANCE
EVERY 3 MONTHS:
• Check air filter condition. Clean or replace if necessary.
EVERY 6 MONTHS:
Follow 3-month maintenance schedule. In addition:
• Clean condensate tray with suitable cleaning agent.
• Clean the grille and panel.
EVERY 12 MONTHS:
Follow 6-month maintenance schedule. In addition:
• Be sure all electrical connections are secure.
• Check condensate pump operation.
• Check the heating and cooling action to confirm proper
operation.
INDOOR UNIT ADDRESSING
For  proper  system  operation,  each  indoor  unit  must  have  a
unique address set from 0 to 63. When setting an address by
remote  controller,  the  outdoor  units,  indoor  units,  and  MDC
must be powered on. If FE is displayed on the LED screen or
display board, this unit has no address. After setting all indoor
units’ addresses, turn off the power supply to all indoor units to
clear errors.
Indoor units’ addressing can be distributed automatically in the
heat pump system. When dip switch “S6” on the outdoor units’
main  PCB  board  is  set  to  00  (default  set  in factory),  indoor
units  are  set  for  auto-addressing. When powering  on  for  the
first time, it takes 6 minutes or more to finish auto-addressing
each indoor unit. The heat recovery system cannot accomplish
this function at this time.
Wireless  Remote  Controller  (40VM900001)  —
Indoor  unit  addressing  can  be  performed  using  the  wireless
remote  controller.  When  using  the  wireless  controller,  user
must maintain a line of sight with receiver on the indoor unit.
See Fig. 24 for a description of buttons on wireless remote.
LEGEND:
ACB
—
Auxiliary Control Board
AUXH
—
Output For Auxiliary Heat
CTON
—
Output For Cooling Operation
FAN
—
Output For Fan Operation
HTON
—
Output For Heating Operation
MAX AMPS 1A
MAX VOLTAGE 24V
CAUTION
When  servicing  or  repairing  this  unit,  use  only  factory-
approved  service  replacement  parts.  Refer  to  the  rating
plate  on  the  unit  for  complete  unit  model  number, serial
number, and company address. Any substitution of parts or
controls not approved by the factory will be at the owner’s
risk and may result in equipment damage.
CAUTION
To avoid equipment damage, do not attempt to reuse any
mechanical  or  electrical  controllers  that  have  been  wet.
Replace defective controller.